Steve Young probably should've stopped at "can't launch with your head. Can't do it," but he goes on to talk about humans being missiles, tucking shoulders, wrapping arms up, and leading bums into things. Better or worse than how he articulated the new rule a couple days earlier?
UPDATE: The NFL's not so great at making it clear, either. Here's the video the league sent to players and coaches, which includes examples of illegal/legal hits.